Sudden steam printer



United States Patent C 3,179,042 SUDDEN STEAM PRINTER Mark Naiman,Philadelphia, Pa., assignor to Sperry Rand Corporation, New York, N.Y.,a corporation of Delaware Filed June 28, 1962, Ser. No. 206,096 4Claims. (Cl. 101-1) This invention relates to printing devices and moreparticularly to that type of printing device wherein there is no directcontact between a moving print means and the surface upon which theprinting is placed.

Despite the advances in computer technology, such as making thearithmetic and other internal organs of the computer faster inoperation, the computing systems as a whole have not increased greatlyin speed of operation. This lack of overall speed increase is due to alarge measure to the relatively low speeds of operation possible withconventional and so-called high-speed types of printing means used toprovide a printed record of the computer output information. Theseprinting devices, when compared to the speed of operation of thecomputer elements themselves, require relatively long period of time forselection of the character to be printed, movement of the character tocontact a surface or the surface to contact the character and return tothe normal intermediary condition. For example, if the printing devicewere a band printer, time would be required to move the band to aposition wherein the character was in proper alignment for printing.Then more time would be consumed in moving the band to contact the paperor move the paper to contact the band and then allow the moving memberto return to its normal intermediary condition, readyfor the next printoperation. In those types of systems in which the printing member is inconstant motion, a period of time is required to allow the print memberto move in its cycle sufiiciently to permit the desired character to bepresented to the surface to be printed upon. The time required formovement to permit contact and the return to a normal condition will besimilar to that of the band printer described above. Further, due to thefact that the paper is permitted to move, during the print operation,usually in a direction transverse to the direction of movement of theprint mechanism the special positioning techniques are required toprevent the individual characters from walking up or down the surface asa row across the width of the surface is printed.

Also, due to the use of light weight bands to support or carry thedesired printing characters, care must be taken to provide properback-up for the bands regardless of whether they are moved or merelystruck by a moving paper depending upon the type of band printeremployed.

Thus, it is obvious that if it were possible to reduce the time requiredto position a character or allow it to rotate until the proper characterwas presented as well as the time required to move the character orpaper the overall speed of operation of the print apparatus and in turn,that of the computational system would be greatly increased.

As briefly stated, this invention makes possible a system of printingwhereby many of the steps required in printing by known conventionalprinting devices are eliminated thereby increasing the overall speed ofoperation. These steps are:

3,179,042 Patented Apr. 20, 1965 (1) Positioning of the print memberwhether by direct movement or by allowing it to rotate until the correctcharacter position is reached.

(2) Contact between character and paper whether the print member ismoved to contact the surface or the surface is moved to contact theprint member; and

(3) Reset or return of the print member to its neutral or normalposition.

The invention employs a matrix composed of individual print means eachof which may print an individual dot. By proper selection of thelocation and number of these dots, there will be printed a particularcharacter or letter in discontinuous form upon the printing surface. Thedensity of the dots making up the letter or character may be as great asdesired simply by arranging for a larger or smaller matrix. Each of theindividual print means which produces a single dot is made in the formof an individual ink steam generator which upon proper excitation willcause a droplet of ink to be deposited upon the surface of the paper.The individual ink steam generating devices consist of a pair ofelectrodes which are emersed in an ink so as to produce a high 1 R loss,that is a high power loss. Upon the application of a voltage to theseelectrodes a current will be passed through the ink contained betweensaid electrodes causing the generation of heat which in turn willvaporize that portion of the ink contained between the electrode tips,which vapor will tend to expand exerting a sufficient pres sure upon theink directly above it, to force individual droplets of ink from the tubeto the surface of the material to be printed upon. The droplets beingguided and confined to an area of the material as determined by the sizeand shape of the tube opening. Each of these actuating devices may inturn be connected to an electronic matrix which can be operated inaccordance with the pattern or character which is desired to be printed.Thus there is no direct contact between a moving print member and thesurface to be printed upon as in conventional print devices, there isonly the indirect type of contact which results from a contact of theprinting ink or fiuid with the surface to be printed upon.

It is therefore an object of this invention to provide a novel form ofprint means wherein no direct contact is made between a moving printingdevice itself and the surface upon which the printing is to be placed.

It is another object of this invention to provide a novel printingdevice not employing pre-formed characters but rather employing a devicewherein a particular form of the character or symbol may be selected atwill.

It is another object of this invention to provide a novel printingdevice the individual unit of which consists of an ink steam generatingunit.

It is a further object of this invention to provide a printing devicewhich operates on the principle of steam generation.

It is yet another object to provide a printing system with an increasedspeed of operation.

It is a further object of this invention to provide a printing devicewhich employs the principles of steam generation to propel the printingink.

Other objects and features of the invention will be pointed out in thefollowing description and claims and illustrated in the accompanyingdrawings, which disclose, by way of example, the principle of theinvention, and

the best modes which have been contemplated for carrying it out.

In the drawings:

FIGURE 1 illustrates a device constructed in accordance with the basicconcept of the invention;

FIGURE 2 shows an arrangement for placing the devices constructed inaccordance with FIGURE 1 in a matrix for printing composite letters orsymbols;

FIGURE 3 shows the manner in which the tape will appear after it hasbeen printed with a device constructed in accordance with thisinvention.

Similar elements will receive similar reference characters in all of therespective figures.

Referring to FIGURE 1 there is shown an individual print elementconstructed in accordance with this invention designated generally as-0. The device consists of a set of electrodes 102 and 104 connected bymeans of leads 106 and 108 to a voltage source 110. The individualelectrodes 102 and 104 are supported by a set of nonconducting supports112 and 114 respectively, and are held in a position so as to provide asmall gap 116 between the respective edges of the electrodes 102 and104. The ends of the electrodes 102 and 104 are placed within a tube 103which tube is closed at its lower end. The upper end of the tube 103 isopen, forming an aperture 122 which is placed either in direct contactor very close to the surface to be printed upon. The aperture 122 may beof any desired size or shape, however, for purposes of illustration inthis example it will be considered to be of circular shape. Ink issupplied to the tube 103 by means of a duct 107 from an ink supply 105.The characteristics of the ink are such that it can easily pass from theopening 122 of the tube 103, but due to surface tension does notnormally do so except under the influence of an external force. The inkis maintained near its boiling point by means of a heater 132 placedwithin the ink supply 105. The ink is kept at this temperature tominimize the requirements of heat which the passage of current fromelectrodes 104 to 102 must produce in order to convert the ink to steam.This will of course allow the use of a smaller value voltage supply 110.In a preferred form of the device the ink must have a high resistance tocurrent flow, thus causing the generation of a great deal of heat topermit the gas expansions as set out above. An ink which has a water orsolvent base will provide such a desired property. Alternatively a lowerresistance ink may be used with a high current value to produce therequired 1 R loss. Placed above the aperture and parallel to it is thesurface of the material to be printed upon 124.

In operation, when it is desired to print an individual spot by means ofthe ink steam printing device it is first necessary to operate thevoltage source 110 by closing the switch 111 to apply via the lines 106and 108 a voltage to the electrodes 102 and 104. In completing the opencircuit between the electrodes 104 and 102 through the gap 116 and theink contained therein, a great deal of heat will be generated due to thehigh resistivity of the high 1 R loss of ink as set forth above. Thislarge amount of heat generated due to the characteristics of the inkwill cause the ink within the area of the gap 116 to become vaporized,ionized and cause any trapped gases, as well as the gas formed toexpand. As a result of this sudden expansion of the gases between theelectrodes a great deal of force is exerted upon the ink directly abovethe level of the electrodes. (The level of the ink in the tube 103 beingmaintained above the electrode level as shown in FIGURE 1 by the levelidentified as 123). This ink is thus propelled out of the open apertureof the tube in the form of individual droplets. Because of therestricted area of the material 124 close to the aperture the dropletsare concentrated and thus produce a well-defined spot.

Referring now to FIGURE 2 there is shown atop view of a matrix employinga plurality of the steam generating devices as shown in FIGURE 1. As canbe seen from the figure the electrode pairs 102 and 104 are arranged ina path along the width and the length of the printing area. Each of theindividual pairs of electrodes 102 and 104- are connected by theirrespective leads 106 and 108 to a voltage source 110. Each voltagesource in turn is connected by a lead to a terminal designated 1, 2 or3. Thus, if the terminal 3 were actuated the voltage source 110connected thereto would apply to the respective lines 106 and 108voltages which in turn would attempt to pass a current through the gap116 of the top left-most pair of electrodes 102 and 104. In the mannerdescribed above at a drop of ink would be printed upon the surface of atape or paper placed above the arrangement shown. Further, if all threeterminals 1, 2 and 3 were actuated at the same time, it would bepossible to get a character similar to the character 1 appearing acrossthe width of the tape composed of three individual dots. If this matrixshown, were extended to include all the remaining electrode pairs itwould be possible to have a character generated, upon operation of theproper terminals, which extended in both dimensions, that is along thelength and width of the printing area. The terminals of the printingmatrix may in turn be connected to switches 111 such as shown in FIGURE1, to a keyboard, or encoder or selection matrix. A matrix which may beemployed with the printer of the invention can be found in High-SpeedComputing Devices by the statf of Engineering Research Associates, Inc.and published by the McGraw-Hill Book Company, Inc. (1950) at page 43.

Although the arrangement shown in FIGURE 2 consists of a small number ofink steam generating units it should be understood that the number maybe increased in either direction to provide as large a character as isdesired as well as to provide a character composed of as many dots alongeach dimension as is desired.

Referring now to FIGURE 3, there is shown a portion of a surface 124which has been printed by devices arranged in accordance with thisinvention and in a matrix arrangement similar to that shown in FIGURE 2.

While a relatively small matrix of printing elements has been shown inthe respective FIGURE 2, larger matrixes may be constructed or aplurality of these matrixes may be employed without departing from theinventive concepts disclosed herein. It will be understood that variousomissions and substitutions and changes of the form and detail of thedevice illustrated in its operation may be made by those skilled in theart, without departing from the spirit of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. Printing means of the type wherein no force is exerted between acharacter forming means and the surface to be printed upon comprising: aplurality of ink tubes placed adjacent and perpendicular to said surfaceto be printed upon, said tubes being sealed at one end and open at theend adjacent said surface; an ink supply, said ink being capable ofpassing current, and having a high 1 R loss, where I is the square ofthe current and R is the resistance of the ink to current flow;connecting means connecting said ink supply to said ink tubes forfilling said ink tubes with ink to a predetermined level; a plurality ofelectrical means, each of said electrical means being mounted in aseparate one of said ink tubes below the surface of said ink level insaid tubes and operable to cause a portion of the ink in its associatedtube to be vaporized; means having a plurality of apertures mountedintermediate said ink tubes and said surface, each aperture beingassociated with a single one of said electrical means, to direct andshape the portion of ink vaporized by its associated electrical means toimpinge upon said surface; and means adapted to receive selectionsignals to selectively operate each of said plurality of electricalmeans whereby the desired printed characters are produced upon saidsurface.

2. A printing means as set forth in claim 1 wherein a means is placed insaid ink supply to preheat the ink 5 in said ink supply.

3. A printing means as set forth in claim 1 wherein each of saidelectrical means is a pair of electrodes.

4. A printing means as set forth in claim 3 wherein a means is placed insaid ink supply to preheat the ink 10 in said ink supply.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS9/56 Denmark. 1/45 Great Britain.

WILLIAM B. PENN, Primary Examiner.

1. PRINTING MEANS OF THE TYPE WHEREIN NO FORCE IS EXERTED BETWEEN ACHARACTER FORMING MEANS AND THE SURFACE TO BE PRINTED UPON COMPRISING: APLURALITY OF INK TUBES PLACED ADJACENT AND PERPENDICULAR TO SAID SURFACETO BE PRINTED UPON, SAID TUBES BEING SEALED AT ONE END AND OPEN AT THEEND ADJACENT SAID SURFACE; AN INK SUPPLY, SAID INK BEING CAPABLE OFPASSING CURRENT, AND HAVING A HIGH I2R LOSS, WHERE I2 IS THE SQUARE OFTHE CURRENT AND R IS THE RESISTANCE OF THE INK TO CURRENT FLOW;CONNECTING MEANS CONNECTING SAID INK SUPPLY TO SAID INK TUBES FORFILLING SAID INK TUBES WITH INK TO A PREDETERMINED LEVEL; A PLURALITY OFELECTRICAL MEANS, EACH OF SAID ELECTRICAL MEANS BEING MOUNTED IN ASEPARATE ONE OF SAID INK TUBES BELOW THE SURFACE OF SAID INK LEVEL INSAID TUBES AND OPERABLE TO CAUSE A PORTION OF THE INK IN ITS ASSOCIATEDTUBE TO BE VAPORIZED; MEANS HAVING A PLURALITY OF APERTURES MOUNTEDINTERMEDIATE SAID INK TUBES AND SAID SURFACE, EACH APERTURE BEINGASSOCIATED WITH A SINGLE ONE OF SAID ELECTRICAL MEANS, TO DIRECT ANDSHAPE THE PORTION OF INK VAPORIZED BY ITS ASSOCIATED ELECTRICAL MEANS TOIMPINGE UPON SAID SURFACE; AND MEANS ADAPTED TO RECEIVE SELECTIONSIGNALS TO SELECTIVELY OPERATE EACH OF SAID PLURALITY OF ELECTRICALMEANS WHEREBY THE DESIRED PRINTED CHARACTERS ARE PRODUCED UPON SAIDSURFACE.